Nanoparticles, described in U.S. Pat. No. 5,145,684, are particles consisting of a poorly soluble therapeutic or diagnostic agent onto which are adsorbed a non-crosslinked surface modifier, and which have an average particle size of less than about 400 nanometers (nm).
Tyloxapol (4-(1,1,3,3-tetramethylbutyl)-phenol polymer with ethylene oxide and formaldehyde) is a nonionic liquid polymer of the alkyl aryl polyether alcohol type. Tyloxapol, also known as "Superinone", ms disclosed as useful as a nonionic surface active agent in a lung surfactant composition in U.S. Pat. No. 4,826,821 and as a stabilizing agent for 2-dimethylaminoethyl 4-n-butylaminobenzoate in U.S. Pat. No. 3,272,700.
The present invention is directed to the use of tyloxapol in nanoparticle formulations. Tyloxapol may act as a stabilizer and/or a dispersant. Tyloxapol also functions as a surface modifier. Tyloxapol serves as an excellent wetting agent and affords enhanced blood pool residence via reduced macrophage uptake.